Roon App quits on Mac Mini M1 after displaying album page

[Hermann_Battenberg]

Roon Core Machine

I run Roon on a Mac mini M1,500 GB, Big Sur 11.6, music library on the internal SSD.

Networking Gear & Setup Details

UpTone EtherREGEN switch
Ethernet

Connected Audio Devices

NAD M10 via Ethernet

Number of Tracks in Library

39,787 tracks

Description of Issue

After the latest Apple update (device support) and a restart the Roon App crashes as soon as it displays the last album played and asks for selecting an audio device. Therefore I cannot even restore from my backup.
What I tried: Reinstalled the app, disconnected all USB devices, started in Recovery Mode, deleted the Startup ojects - all resulted in no change!
I set up Roon on my iMac with the same system including the latest update, and it runs fine there. I had to disconnect the Roon core on the Mac mini. I tried to start the Roon App on the Mac mini after that, but without success - it crashes after notifying me that Roon already runs on another device.

Before I restore my Mac Mini to a Backup of a week ago I would be grateful for tips to get the app running again!

Thanks for any help.

[Hermann_Battenberg]

Update:
Today I took the time to reinstall the System (Big Sur) - no change.
Then I restored the data from a week old backup: Voilá - I could start Roon again!
I had to then restore Roon from a 2 days old backup, and I am back and able to listen to everything again.